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Readers' brains go native

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4:49pm, June 21, 2002
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Some people cough up a lot of dough to master the tough task of reading in English.

Consider the difficulty of learning to read the words cough, dough, and tough, given their nearly identical spellings and vastly different pronunciations.

Unable to rely on consistent ties between letters and sounds, English readers often use additional strategies to decode written words. As a result, their reading-related brain activity differs in intriguing ways from that of Italians reading their native language, in which letters almost always correspond to consistent sounds, a new study suggests.

Two brain areas involved in remembering words exhibit the most activity as native English readers read English words, according to a team of neuroscientists led by Uta Frith of University College London and Eraldo Paulesu of the University of Milan-Bicocca. The areas lie within an extensive brain network previously linked to reading comprehension.

In contrast, another part of this brain network—already implicated in the process of matching letters to corresponding sounds—displays the most activity as Italians read Italian words, the scientists say.

The researchers used positron emission tomography scans to measure blood-flow changes in volunteers' brains while they read words. This technique indirectly charts rises or falls in cellular activity in different brain regions.

Different spelling systems, and perhaps other culture-specific ways of organizing knowledge, markedly influence brain function, the researchers contend in the January Nature Neuroscience.

When presented with a list of words to read aloud in their respective languages, six English college students took much longer to begin reading each word than six Italian college students did. This disparity increased when the students read pronounceable nonsense words.

Such findings support the idea that Italian readers pronounce words mainly by translating letters into sounds, while English readers must adopt additional tactics, such as considering word meanings, to decide on pronunciation, according to Frith and her colleagues.

Scientists do not yet know how the brain regions identified underwrite the ability to read, remarks psychologist Julie A. Fiez of the University of Pittsburgh in a comment published in the same journal.

Various types of reading instruction, such as those focusing on phonics or word meanings (SN: 8/28/93, p. 132), may affect brain development in different ways, Fiez suggests.

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